Gesture is widely used in daily life of people as a common communication way. With rapid development of computer technology in recent years, research on gesture recognition to introduce gesture into man-machine interfaces has drawn great attraction and made great progresses.
As conventional man-machine interactive input devices, keyboards play an important role. The common keyboards nowadays include physical hardware keyboards and touchscreen soft keyboards. However, due to the limitation of size, the two kinds of keyboards cannot provide both portability and ease of operation. In view of this, virtual input devices have been proposed.
The existing virtual keyboards typically use projection of keyboard to form a desired keyboard image by using light projection when needed, and use a single camera to acquire images of a user's input actions, and then recognize images to obtain input results. However, due to use of light and camera, such virtual keyboards are not convenient to use and carry.
In view of this, there is a requirement to provide a virtual input device which is easy to use and carry.